It was also demonstrated that the polarization state of Bessel beams of arbitrary order, propagating along a straight line, can be varied along their propagation [1]}. Moreover, the intensity and hollow core radius of a Bessel beam of arbitrary order were shown to be tunable along the optical axis [2]}, [3]}. Furthermore, Bessel beams with controllable intensity profiles along arbitrary trajectories were designed and observed [4]}. Beams with a varying OAM along their propagation have also been suggested [5]}, [6]}, [7]}. We treat the OAM as the value of the number l associated with the presence of the function \(e^{i l\phi }\)  in the complex amplitude distribution of the beam, where \(\phi =atan(\frac{y}{x})\) . For beams which are eigenstates of the orbital angular momentum, \(l\)  is known as the topological charge. The interpretation we use here is a local one, associated with the distribution of the beam around an area of interest.
